This invention is in the field of focal-plane image detectors. Such detectors usually consist of a two-dimensional array of small conductor photodetectors and are made by two major methods. In the case of mercury cadmium telluride (HgCdTe) photodetectors, one method consists of bonding discrete photodetectors to a silicon substrate. The other major method consists of growing an epilayer of mercury cadmium telluride on a cadmium telluride substrate. The one method is difficult to perform with large, high-density arrays, and the other method requires steps to delineate individual detectors for crosstalk prevention. For detectors other than HgCdTe, similar methods, or other methods, may be used.